Correct.. I'll say it again - I use the default media that comes with the device. Whatever way you would normally raise the volume of any other application should raise the volume here as well. I don't provide any volume control in the application itself.

I don't know if Advanced Backlight messes with anything or not, but part of the N8x0 desktop itself includes a speaker icon in the top right that you slide right and left and that turns the volume up for all your system sounds, notification sounds, etc. and also should mess with the volume of pyRadio.

This picture is a random one I found on Google looking for N800 Diablo and surprisingly it's hosted here somewhere:


Now, that icon looks different than mine, but it's in the same place, it's a small speaker icon up next to the green dot and wireless icon.

On my N810 I have a Bluetooth icon, Backlight icon, Speaker Icon, Wireless Icon, and Battery Icon.

That speaker icon turns my pyRadio up and down without doing anything in pyRadio itself. It's possible you have third party software installed that has messed with OSSO or 'enhanced' something in some way but is messing with the systems ability to raise/lower the volume. But there should be no reason that you need the Media Player open in addition to the regular speaker slider at the top of the desktop.